Treatment of fatty acid esters and production of high molecular weight alcohols therefrom



2,809,206 Patented Oct. 8, 1957 United States Patent Ofifice TREATMENTOF FATTY ACID ESTERS AND PRO- DUCTION OF HIGH MOLECULAR WEIGHT AL-COHOLS THEREFROM Glenn R. Wilson and Marguerite S. Baylerian, Detroit,Mich., assignors to Ethyl Corporation, New York, N. Y., a corporation ofDelaware No Drawing. Application April 21, 1954, Serial No. 424,744

13 Claims. (Cl. 260--410.)

This invention relates to the treatment of fatty acid esters and inparticular is concerned with an'improved process for treating fatty acidesters with mineral acids prior to their reduction to produce thederivative alcohols.

It has long been commercial practice to treat fatty acid esters ofanimal and vegetable origin with mineral acids, especially sulfuricacid, for the purposes of refinement. Briefly, such treatment involvesheating the fats and oils to temperatures up to about 100 C. in thepresence of sulfuric acid over a prolonged period of time. The mixtureis then washed with water to remove the acid and the fat or oil isfiltered to remove solid constituents. Still other treatments of fatsand oils are known such as caustic treatment, high temperature heating,and the like. However, none of these prior art processes has provensatisfactory for the preparation of a product which is readily adaptableto reduction in an alkali metal-alcohol reducing process without theformation of stable emulsions in the hydrolysis step of this latterprocess.

The alkali metal-alcohol reducing process has likewise long been knownand is commonly referred to as the Bouveault-Blanc process. This processinvolves treating fatty acid esters simultaneously with an alkali metaland a reducing alcohol, hydrolyzing the alcoholates so-formed andseparating the alcohols therefrom. It is in the hydrolysis step of thisprocess that the stable emulsions are encountered. These emulsions havenecessitated longer residence times and considerable delay in productionsince the time required for breaking them was varied from about one-halfhour to many hours in the absence of costly emulsion inhibitors. Inorder to obviate this problem, it has previously been proposed to reducethe ratio of solvent to the reducing alcohol in the hydrolysis step andalso to add certain compounds as emulsion inhibitors such as phenoliccompounds and other expensive inhibitors. However, these methods areeither timeconsuming, costly, or contaminate the products. Accordingly,a solution to this problem would be of particular benefit to the art andprovide a material which is especially suitable for reduction by analkali metal-reducing alcohol process.

It is an object of this invention to provide an improved process fortreating fatty acid esters. A specific object of this invention is totreat fats and oils or fatty acid esters with a mineral acid in a mannerwhich will result in a product of improved characteristics, especiallyadaptable for reduction to provide high molecular weight alcohols. Astill further object of this invention is to provide a new and novelprocess for the production of high molecular weight alcohols. These andother objects will become apparent from the discussion hereinafter.

The above and other objects of this invention are accomplished bytreating fatty acid esters dissolved in an inert organic liquid with amineral acid in the presence of an alcohol. It is preferable to treatthe esters under essentially reflux conditions-that is, within about 15C. of the reflux temperatureof the mixture, preferably for a period oftime between about 0.5 and 180 minutes.

It is also preferable for best results to treat the fatty acid estersdissolved in at least 0.25 part of inert organic liquid per part ofester with a mineral acid under essentially reflux conditions in thepresence of an alcohol in a proportion sufficient to provide an excessover that required to esterify the free fatty acids. Best results areachi ved when the proportion of the alcohol is at least 20 percent ofthechemical equivalent based upon the fatty acid ester in an alkali metalalcohol reduction process, and this quantity is still in excess of thatrequired to esterify the free fatty acids. In a still more particularembodiment of this invention, fatty acid esters dissolved in at least0.25 part by weight of inert organic liquid per part of said ester aretreated with a mineral acid, especially sulfuric acid, in essentiallycatalytic quantities, and the treatment is conducted under essentiallyreflux conditions for a period of time between about 0.5 to minutes inthe presence of an alcohol in proportion which will provide an excessover the theoretical quantity required to esterify the free fatty acids,and this proportion is at least 20 percent of the chemical equivalentbased upon the fatty acid ester in an alkali metal-alcohol reductionprocess and an excess of water over the theoretical based upon the freefatty acids is collected. It has been found that when treating fattyacid esters in this manner, the product thereby resulting when subjectedto an alkali metal-alcohol reducing process does not form the stableemulsions in the hydrolysis step of this process. Thus, one aspect ofthis invention is the combination of treating fatty acid esters with amineral acid as described and subjecting the so-treated esters to analkali metalalcohol reducing process. By our process the fatty acidesters are treated in a manner which will result in a product which,when subjected to an alkali metal-alcohol reducing process, will form anemulsion-free mixture in the hydrolysis step of this process. The term,emulsion free, is intended to connote a mixture having no emulsion, orif an emulsion does form, it will break within a period of about 10minutes and preferably about 5 minutes. When a reduction process is tofollow the treatment of the esters, it is preferable to employ aquantity of inert organic liquid and alcohol in the acid treat mixturewhich would be employed in the ester reduction process. By this method,the esters are treated and can be immediately reduced without additionaloperations. In still another embodiment of this invention, fatty acidesters are transesterified by reacting with an aliphatic alcohol in thepresence of an alkaline alcoholysis catalyst. The newly formed estersdissolved in an inert organic liquid are treated with a mineral acidunder essentially reflux conditions and in the presence of an alcohol,and the so-transesterified and treated esters are reduced by an alkalimetal-reducing alcohol process to produce the corresponding alcohols.

The process of this invention as pointed out in its broadest aspectsabove has the particular advantage of providing a product ofacid-treated fatty acid esters which when subsequently reduced by analkali metalalcohol reducing process do not result in stable emulsionsin the hydrolysis step of this process. This feature is especiallyattractive to the industry inasmuch as it eliminates the costly andtime-consuming emulsions which ordinarily must set for many hours oreven days before the emulsions break or in some instances never dobreak. Further advantage is found when the proportions of the inertorganic liquid and reducing alcohol in the acid treat step areessentially the same as those required for direct reduction. Thepresence of the reducing alcohol in the acid treat operation esterifiesthe free fatty acids, thus giving a higher yield of the fatty alcoholand decreasing the amount of soaps obtained. Further, the

alcohol re-esterifies any free fatty acids which might be formed. Theprocess lends itself readily to a continuous operation without thenecessity of drying, filtering, or other unit operations ordinarilyrequired in other treatments of fatty acid esters or fats and oils ofanimal and vegetable origin.

To further demonstrate the process of this invention, reference is madeto the following examples wherein all proportions are parts by weightunless otherwise specified.

EXAMPLE I To a reactor equipped with a heating means, a means foragitation, and a reflux condenser having a water trap is added a mixtureof 100 parts of tallow, having a saponification number of 195 and anacid number of 1.0, 100 parts of toluene, 23 parts ofmethylisobutylcarbinol, and 0.35 parts of concentrated sulfuric acid.The mixture was heated to the reflux temperature and maintained at thattemperature for a period of about 60 minutes. From the vapors, water iscondensed and collected in the Water trap equivalent to the moisturecontent of the starting materials, and about 5 theories additional waterbased on esterification of free fatty acids. The toluene is returned tothe reaction vessel. The product thus obtained, when subsequentlyreduced by an alkali metal-alcohol process, will be emulsion-free in thehydrolysis step of said reduction process.

EXAMPLE II To a reactor equipped with a heating means, a means foragitation, and a reflux condenser equipped with a water trap was added amixture of 100 parts of soy bean oil, having a saponification number of199.5 and an acid number of 0.6. 100 parts of toluene, 76.4 parts ofmethylisobutylcarbinol, and 0.367 parts of concentrated sulfuric acid.The mixture was heated to the reflux temperature, about 110 C., andmaintained under refluxing conditions for 60 minutes. During thisperiod, 0.25 parts by weight of water was collected in the trap, about0.2 parts of which were residual moisture. Without any furthertreatment, the mixture was then continuously fed to a dispersion, havingan average particle size of 20 microns, of 34.5 parts of sodium in about130 parts of toluene. The reaction mixture was maintained under anitrogen atmosphere and at reflux conditions for a period of about 19minutes. Upon initial feeding of the mixture to the sodium dispersion.hold-up of toluene was commenced and a total of 130 parts of toluenewere removed by about minutes after commencement of the feed to thedispersion. At the end of the l9-minute reaction period, the mixture wascooked for an additional 5 minutes. This reduction mixture was thenadded to 167 parts of hot water while continuously being agitated, andthe temperature of the hydrolysis mixture rose without control. Thetemperature thus varied between about 60 and 100. At the completion ofthe addition of the reduction mixture to the water, agitation wasstopped. Onehalf minute after the agitation was stopped, the emulsionbroke. The lower water layer containing caustic and glycerine wasremoved and the upper organic layer was fractionally distilled toseparate the solvent and reducing alcohol from the product alcohols. Thesolvent and reducing alcohol were then recycled to the acid treatoperation.

In contrast, when the same proportions of the above soy bean oil,solvent, alkali metal dispersion, and reducing alcohol were reactedessentially as described above, but without the pretreatment, anemulsion resulted in the hydrolysis step which did not break afterstanding for I 180 minutes.

EXAMPLE III The procedure was followed essentially the same as describedin Example II, except that 0.36 parts of concentrated sulfuric acid Wasemployed, the reflux time was 120 minutes, and the material treated washydrogenated tallow, having a saponification number of 205 and an acidnumber of 7.1. Exclusive of residual moisture, 0.49 parts of water wascollected, representing about 2 theories based upon the free fatty acidcontent. The proportions of toluene and tallow were parts each, andsuflicient methylisobutylcarbinol was incorporated in the mixture toesterify the free fatty acids plus 5 percent excess of this alcohol overthat required in the reduction step. After reduction using 5 percentexcess sodium dispersed in toluene and hydrolysis, the emulsion whichformed broke in 3 to 4 minutes. Another 100 parts of this same materialwas treated essentially the same as above, except that 0.734 parts ofconcentrated sulfuric acid was employed, the reflux time was 60 minutes,and the amount of water collected, excluding residual water, was 0.59parts. Upon completion of the reduction and hydrolysis of the reductionmixture, the emulsion broke in 4 minutes. Thus, it can be seen that witha given raw material, the period of reflux is inversely proportional tothe quantity of concentrated sulfuric acid to be employed.

In contrast to the above results, another portion of the hydrogenatedtallow, which had not been treated with concentrated sulfuric acid asdescribed, was reduced and an emulsion resulted during hydrolysis whichdid not break after standing for a period of 100 minutes.

EXAMPLE IV Into a reaction vessel essentially the same as that describedabove was placed 100 parts of tallow having a saponification number of195 and an acid number of 1.0 and 70 parts of toluene. Three-fourthspart of sodium was added to 113 parts of methylisobutylcarbinol, and theresulting solution was added to the solution of tallow and toluene. Thereaction mixture was then heated to the reflux temperature, about C.,and refluxed for minutes. At the end of this time, the reaction mixturewas neutralized with sulfuric acid, cooled, and two layers observed.Thus, the tallow glycerides were transesterified withmethylisobutylcarbinol. The lower layer comprising essentially glycerolwas removed and found to contain about 76 percent of the theoreticalamount of glycerol. To the upper organic layer is added an additional 30parts of toluene. Then about 0.35 parts of concentrated sulfuric acid isadded to this mixture, and the mixture is heated to the refluxingtemperature and refluxed for about 60 minutes. During this time, waterwhich is formed is collected in the water trap. Thus, themethylisobutylcarbinol esters of the fatty acids of tallow have beenacid treated. At the completion of this period, the reaction mixture isthen fed to another similar reactor containing a previously prepareddispersion of 33.4 parts of sodium in parts of toluene. This reductionreaction mixture is maintained under a nitrogen atmosphere and heated toreflux conditions. Upon starting the feed of the mixture to the sodiumdispersion, hold-up of toluene is commenced and a total of 130 partswhich is evident will break in less than 10 minutes.

To further demonstrate the process of this invention, reference is madeto the following table wherein contrast is shown of the emulsion breaktime of various materials when reduced and hydrolyzed in the absence ofand with treating according to our invention. In each instance, theoriginal treat mixture contained the required amount ofmethylisobutylcarbinol to esterify the free fatty acids and to provide 5percent excess of the theoretical quantity" required to reduce theesters; A 1 to 1 solvent to ester ratio was employed.

H20 Emul- Goned Reflux Col- Theoret. sion Starting Material Wt. H28 04Time leeted H2O Break- Wt. (Min.) (Wt) l time (MiJL) Hydrogenated tallow100 0 0 110 Sap. N0. 200 100 0.1 60 0. 15 0. 012 5 Acid No. 0.4 100 0.260 0.25 0.012 3% Edible Tallow- 100 0 0 0 100 Sap. N0. 195.0 100 0. 2 600 1 0. 032 11 Acid No. 1.0- O. 3 6O 0 l 0. 032 3. Fancy Tallow- 0 0 0 30Sap. No. 190.7- 0. 4 60 0. 59 0. 11 1 Acid No. 3.4--- 0. 2 60 0. 39 0.112

' Moisture content of starting materials not included.

In examining the above table, it- .can readily be seen that in treatinga given starting material with acid to reduce the emulsion break period,the period of reflux time is inversely proportional to the quantity ofacid employed. Because of the variance in nature and analysisof thestarting materials, as exemplified above with three grades of tallow,the quantity of acid to be employed and the reflux time is bestdetermined experimentally on a small scale before conversion to acommercial operation. That is, a sample of the raw material is treatedaccording to this invention with the acid in various quantities andunder various reflux periods to determine that quantity of acid whichfor a given reflux period will result in a product-which, upon reductiznand hydrolysis, will form an emulsion-free mixture. However, in general,irrespective of the starting'material to be employed, it is preferredhere that between about 2 to 0.05 parts by weight of the concentratedmineral acid to 100 parts by weight of the fatty acid esters be employedand the treat time be between about 0.5 minutes and 180 minutes. Bestresults are obtained when the proportion of the mineral acid is betweenabout 1.05 to 0.05 parts to 100 parts by weight of the fatty acidesters, and the reflux period is about 60 minutes.

We employ mineral acids in the treatment ofthe fatty acid esters.Generally speaking, any mineral acid can be employed, but the oxidizingmineral acids are preferred, especially sulfuric acid. Other mineralacids which can be employed are, for example, nitric, permanganic,chromic, and the like. It is also most preferable to employ theoxidizing mineral acids in their con- 'centrated form, that is, aboveabout 95 percent by weight. .Lesser concentrations can be employed,however, these :are not desirable in that appreciable quantities ofwater will be introduced which should be removed, especially when thetreated fatty acid esters are to be reduced by an alkali metal-alcoholreducing process.

The organic liquids which we employ as solvents should be inert to thereactants, namely, the fatty acid esters, the treating acid, and theesterifying alcohol. If the treated fatty acid esters are to be laterreduced, which is the preferred embodiment of this invention, the inertorganic liquid should also be non-reactive with alkali metal andessentially immiscible with water. The inert organic liquids which weespecially prefer are the hydrocarbons such as toluene, xylene,dihydronaphthalene, petroleum fractions, heavy alkylates, kerosene,benzene, the octanes, nonanes and decanes, mineral oil, tetralin,cumene, decalin, and the like. Another criterion of choice of solvent isthat it have a boiling point approaching that of reaction conditions andpreferably one which will form a water azeotrope. By employing thesepreferred solvents, water is removed from the reaction mixture whichwould hinder the treat and esterification of 1 the free fatty acids.Still other solvents can be employed as,-for example, alcohols, ethers,and the like, providing 7 6 proportion of inert organic liquid employedcan be varied within wide limits. However, best results are achievedwhen at least 0.25 parts by weight of the liquid .per part by weight offatty acid ester is employed. Proportions below this limit are notsatisfactory in that insufiicient contact with the moisture is obtained,thus preventing efficient removal of this moisture from the reactionmixture during reflux and permitting reverse equilibrium of theesterification. When the treatment is to be followed by reduction whichis the preferred embodiment of this invention, the solvent is generallyemployed in proportions between about 0.25 to 10 parts per part byweight of fatty acid ester. In most instances, proportions of the inertorganic liquid above 1.3 parts per partof fatty acid ester are notrequired. Thus, good results are achieved when between about 0.25 to 1.3parts by weight of solvent to 1 part byweight of fatty acid ester areemployed. The alcohols employed in theacid treat can be any primary,secondary, or tertiary alcohol, and preferably those which are liquidsunder the reaction conditions. The secondary alcohols are employed whenthe treatment is to be followed by reduction primarily due to theirlesser reactivity with the alkali metal. Among such alcoholsare, forexample, propanol-Z, butanol-Z, pentanol-Z, pentanol-3,2-methylbutanol-3, methylisobutyl- .carbinol, cyclohexanol,cyclopentanol, phenylethyl carbino], and the like.

Still other secondary alcohols can be employed, the foregoing servingmerely as illustrative examples. Likewise, the tertiary alcohols such astertiary butyl, and tertiary amyl, can be used with good results.Theprimary alcohols can be used but have not been found to be assatisfactory as the secondary or tertiary alcohols. The proportion ofthe alcohol to be employed is preferably in excess of that required toesterify the free fatty acids. Best results are obtained when theproportion of alcohol is in excess of that required to esterify the freefatty acids and is at least 20 percent of the chemical equivalent ofalcohol based upon the fatty acid esters. In the preferred embodimentwherein the tr;:ated esters are reduced, it is advantageous to employsufficient alcohol to esterify the free fatty acids and provide anexcess of about Spercent over the quantity required in the reductionstep. The incorporation of the requisite amounts of solvent and alcoholfor reduction in the acid treatment provides a mixture suitable fordirect reduction without the necessity of intermediate distillation,addition, or separation.

It should be pointed out that the incorporation of an alcohol in ourtreatment is primarily to esterify the free fatty acids. However, suchesteriflcation in the absence of the specific acid treatment of ourprocess has no appreciable effect in the emulsion characteristics of theproduct when subsequently reduced. For example, runs were conducted inwhich simple esterification of the free fatty acid content of the rawmaterial was obtained by reaction with a secondary alcohol in thepresence of sulfuric acid as a catalyst. When the resulting material wasreduced, no appreciable change in the breaking time of the emulsionwhich formed was exhibited. The emulsion break-time was again aboutminutes, thus mere esterification of the free fatty acids does noteliminate this problem.

As noted, more than the theoretical quantity of water, excludingresidual moisture of starting materials, over that obtained fromesterification of the free fatty acids is collected. In general, thefatty acid esters are treated in a manner to collect between about 1.05and 20 theories of water based upon the free fatty acid content. It ispreferred here to remove between about 2. and 10 theories of water.Removal of such excess water during the treatment results in asubstantial lowering of the emulsion break-time in a reduction process.

Our process is particularly adaptable to treating the fatty acid esters'of tallow. Among such esters are the naturally occurring glycerides oftallow, hydrogenated -tallow, and tallow which has been transesterifiedwith other alcohols than glycerol. In treating tallow, it has been foundthat best results are achieved when between about 0.75 and 0.2 parts byweight of mineral acid per 100 parts by weight of tallow are employed inthe presence of about 1 part by weight of toluene per part by weight oftallow, at a reflux time of between about 40 and 120 minutes in thepresence of at least 50 percent of the chemical equivalent of an alcoholbased on the ester. It has been found that these conditions provide aproduct of tallow fatty acid esters which, when subsequently reduced. donot form an emulsion in the hydrolysis step which will not break withinabout minutes.

The process of this invention can be applied to numerous other fattyacid esters. Among such materials are babassu, coconut, castor, palm,sperm, peanut, carnauba, cashew nut, cotton seed, linseed, soybean,menhaden, and the like fats. oils, or waxes. Still other fats, oils, andwaxes can be treated according to the process of this invention, theforegoing serving merely as illustrative examples. Likewise, themonoesters of these materials obtained by transesterification or othermethods can be employed in the process of this invention. Similarly,hydrogenated or partially hydrogenated triglycerides or monoesters offatty acids can be treated according to this process. In general, theesters of acids having between about 8 and carbon atoms can be employed.Particular oils or esters which can be treated in this fashion are thosewhich by prior art methods have resulted in stable emulsions in thehydrolysis step of an alkali metal-alcohol reducing process.

In some instances when treating the fatty acid esters with a mineralacid, there will be a tendency of the reaction mixture to foam. In orderto obviate this difficulty, we prefer to employ a reaction vessel inwhich the upper portion contains a cooling coil or other foambreakingmeans. The cooling coil knocks down the foam and prevents it from beingentrained in the refluxing vapors. Other methods for eliminating thefoam can be employed as, for example, defoaming agents and the like. Itis also advantageous to provide efficient agitation to the reactionmixture. These and other modifications will be apparent.

A particular embodiment of this invention is treating fatty acid esterswith a mineral acid and then subjecting the so-treated fatty acid estersto an alkali metal-alcohol reducing process. This operation broadlyconsists of treating the fatty acid esters simultaneously with an alkalimetal and reducing alcohol, hydrolyzing the resultant mixture, andseparating the product alcohols therefrom. The alkali metal can beemployed in either a solid or liquid form. In either event, it ispreferred that the metal be utilized in the form of finely dividedparticles, and hence, alkali metal dispersions, especially sodiumdispersions are particularly well suited for this process. Thedispersion is a suspension of finely divided metal uniformly dispersedand suspended in an inert liquid, preferably a hydrocarbon. Thesedispersions are well known and are ordinarily prepared by vigorouslyagitating a mixture of sodium in a dispersion medium at a temperatureabove the melting point of sodium but below the boiling point of thedispersion medium. The dispersion medium can be any of those media whichare commonly employed. It is preferred to employ as a dispersion mediuminert organic liquids especially the hydrocarbons and especially theinert organic liquid which is employed in the acid treat operation. Theconcentration of sodium in such a dispersion most common is up to about60 percent by weight. It is preferred here to employ a dispersion ofabout 50 percent by weight or less. The particle size of the sodium willvary from very minute particles up to about 50 microns in size. In apreferred embodiment, the average particle size should be below 20microns. The preferred specifications of the alkali metal dispersion aspresented above have been found to be more eflicient in an alkalimetal-alcohol reduction process.

The quantity of alkali metal and reducing alcohol em ployed in thereduction step can be varied within wide limits. In a preferredembodiment, these materials are used according to the theoreticalquantity and up to about 5 percent in excess of that quantity as shownin the following equations, wherein Equation I describes the re ductionof fatty acid esters comprising essentially triglycerides, and EquationII shows the reduction of fatty acid monoesters.

Equation 1 RCHzOM RrCHzOM RzOHzQM 6ROM (IE-OM H2OM Equation II In bothequations, R, R1, and R2 can be the same or different and are carbonchains having between about 8 and 40 carbon atoms; R and R" can be thesame or different and are alkyl or cycloalkyl radicals of the alcoholsmentioned previously; and M is an alkali metal.

When solvents are employed in conducting the reduction step of thisprocess, they can be any solvent which is substantially unreactive withthe particular reactants such as hydrocarbons, alcohols, ethers, and thelike. Generally, it is preferred to use the same solvent which isemployed in the acid treat or in the preparation of the alkali metaldispersion, as set forth previously. The use of a solvent is frequentlydesirable in order to maintain the fluidity of the reaction mixture. Toachieve adequate fluidity, the proportion of solvent to ester can be ashigh as about 10 to 1 parts by weight. However, because of thepretreatment operation and other features of this invention, excessivequantities of solvent are not required. In fact, quantities less thanabout 1.3 parts by weight of solvent per part by weight of fatty acidester are generally found to be suflicient. In a preferred embodiment,the solvent to ester ratio is maintained between about 0.25 and 1.3 to1.

It has been found that when a combination of the acid treatment andreduction process is employed, the above limits in the reduction processprovide the best results for the production of the high molecular weightalcohols. Thus, it is preferable to employ the same solvent and alcoholin each of these steps in their requisite amounts as pointed out above,taking into account variables such as free acid content, fluidity,excesses, and the like. It should, however, be understood that thesolvent or alcohol in the acid treat need not be the same as the solventor alcohol employed in the ester reduction. That is, different solventsor alcohols can be employed in each step and in some instances,particular advantage can be achieved although such variation in thematerials has not been found necessary.

Another embodiment of this invention is to transesterify the fatty acidesters prior to conducting the actual reduction process. Such aprocedure has been found to be beneficial in the case of triglycerides,inasmuch as the glycerine is more readily separated and recovered.Briefly, the transesterification comprises reacting a glyceryl ester ofa fatty acid with an aliphatic alcohol in the presence of an alkalinealcoholysis catalyst and recovering the newly formed esters and glyceroltherefrom. In some instances, it is desirable to conduct thetransesterification in the presence of a solvent. In this instance, itis preferred to employ the same solvent as that which is] employed 'inthe ason's o3 acid treat step; It is further preferred to react theglycerylesters ofthe-fatty acids with an aliphatic alcohol containing atleast 2 carbon atoms, in the presence of an alkaline alcoholysiscatalyst and, when em'ployed, in the presence,- of at least '20 percent,based upon the weight of the glyceryl ester used, of solvent; Preferredalcoholysis; catalysts are the alkali metal hydroxides, alkali metalamides, alkali metal hydrides, and the like. Any alcohol can'be employedas the esteiifying alcohol, that is, primary, secondary, or tertiaryalcohols, although the secondary alcohols, particularlymethylisobutylcarbinol, are preferred here. The transesterificationstepcan be conducted either prior to the acid treatment stepor after theacidtreatment and prior to the ester reduction stage; In thepreferred'embodiment, the transesterification is conducted prior to theacid treat, thus eliminating a neutralization step and providing moreeconomical employment of the esterification catalyst and treating acid.In this operation, the resulting monoesters have also been found to bemore readily adaptable to an ester reduction process, particularly whenthe secondary alcohols are employed as the transesterifying alcohol.

If the treated fatty acid esters are not to be employed in an esterreduction operation, it is preferable to neutralize the mineral acid inorder to obviate the possibility of deterioration of the product by theacid. If the treated fatty acid esters are to be reduced, it ispreferable that they be reduced as described above without intermittentstorage. The treated fatty acid esters can be stored withoutneutralization or other similar operations, although storing forprolonged periods is not preferred.

As mentioned previously, the process of this invention finds particularutility in providing treated fatty acid esters which do not result in astable emulsion when subsequently reduced by an alkali metal-reducingalcohol process. The treated fatty acid esters can also be usedas such,as plasticizers, intermediates for other chemicals, additives tolubricants, paint and varnishes, and the like. When the treated fattyacid esters are reduced, the alcohols obtained thereby are particularlyuseful in the preparation of detergents, wetting agents, otherchemicals, and the like. These and other uses will be apparent.

Having thus described our process, it is not intended that it be limitedexcept as noted in the appended claims.

We claim:

1. A process which comprises heating crude esters of fatty acids havingfrom 8 to 40 carbon atoms per molecule with a mineral acid underessentially reflux conditions in the presence of a monohydric alcoholand dissolved in an inert organic liquid selected from the groupconsisting of hydrocarbons, ethers, and excess alcohol, for a periodsufiicient to generate more than the theoretical quantity of water basedupon esterification of the free fatty acids and the moisture content ofthe starting materials, andseparating at least about 1.05 theories ofsaid water from the reaction mixture during said heating.

2. A process which comprises heating for about 60 minutes crude estersof fatty acids having from 8 to 40 carbon atoms per molecule withsulfuric acid under essentially reflux conditions in the presence of amonohydric alcohol and with the ester dissolved in an inert hydrocarbonliquid, the proportion of the sulfuric acid being between about 1.0 to0.05 part for every 100 parts by Weight of the esters, and continuallyseparating water from the reaction mixture as it is heated, to driveoff. any initial moisture content as well as from 1.05 to 20 theories ofadditional moisture based upon the esterification of the free acidcontent.

3. An improved process for the production of high molecular weightalcohols from crude esters of fatty acids having between 8 and 40 carbonatoms per molecule, comprising heating said esters with a mineral acidunder essen tially reflux conditions in the presence of a monohydricalcohol and dissolved in an inert organic liquid selected from the groupconsisting. of hydrocarbons, ethers, and excess alcohohand during theheating separating from the reaction, mixture, the moisture itoriginally contained and at least about, 1.05 theories -of additionalwater based upon esterification. of the free fatty acids, in the,esters, and subjecting the so-tr'eatedesters to an, alkalimetalrreducing alcohol process to produce the corresponding a1- cohols.

4. An improved, process for the production of high molecular weightalcohols from crude esters of fatty acids having between, 8: andy 40-carbon atomsv per molecule, comprising heating said esters dissolved inan inert hydrocarbon liquidwith sulfuric acid under essentially refluxconditions in the. presence of a monohydric alcohol for about 60minutes, and during the heating separating from the reaction mixturebetween about 1.05 to 20 theories of water based upon esterification ofthe free fatty acids and the moisture content of the starting materials,the proportion of sulfuric acid being between about 1.0 to 0.05 partsfor every parts by weight of fatty acid esters, and subjecting theso-treated esters to an alkali metal-reducing alcohol process to producethe corresponding alcohols.

5. An improved process for the production of high molecular weightalcohols from crude fats which comprises transesterifying said fats byreacting with an aliphatic monohydric alcohol in the presence of analkaline alcoholysis catalyst, heating the so-transesterified fatty acidesters with a mineral acid under essentially reflux conditions in thepresence of a monohydric alcohol and dissolved in an inert organicliquid selected from the group consisting of hydrocarbons, ethers, andexcess alcohol for a period sufiicient to generate more than thetheoretical quantity of water based upon esterification of the freefatty acids, and during the heating separating the moisture content ofthe starting materials along with at least about 1.05 theories of saidesterification water, and subjecting the so-transesterified and treatedesters to an alkali metal reducing alcohol process to produce thecorresponding alcohols.

6. The process of claim 5 wherein the alkali metalreducing alcoholprocess comprises reacting the so-transesterifi'ed and treated fattyacid esters with between about the stoichiometric quantity and about 5percent in excess of that quantity of sodium and between about thestoichiometric quantity and 5 percent in excess of that quantity ofmethylisobutylcarbinol in the presence of between about 0.25 to 1.3parts by weight of an inert organic liquid selected from the groupconsisting of hydrocarbons, ethers, and excess alcohol.

7. An improved process for the production of high molecular weightalcohols derived from tallow, which comprises heating about l00 parts byweight of said tallow dissolved in about 100 parts by weight of toluenewith between about 0.2 and 0.75 parts by weight of concentrated sulfuricacid under essentially reflux conditions for a period of time betweenabout 40 and minutes, during the heating separating from the reactionmixture at least about 1.05 theories of water based upon esterificationof the free fatty acids and the moisture content of the startingmaterials, and then reducing the so-treated esters by thesodium-reducing alcohol method.

8. The process of claim 1 wherein said inert organic liquid is ahydrocarbon.

9. The process of claim 1 wherein the quantity of water recovered isbetween about 2 and 10 theories.

10. The process of claim 3 wherein said inert organic liquid is ahydrocarbon.

11. The process of claim 5 wherein said inert organic liquid is ahydrocarbon.

12. A process which comprises heating about 100 parts. of tallowdissolved in about 100 parts of toluene with between about 0.2 and 0.75parts of concentrated sulfuric acid under essentially reflux conditionsfor a period of time between about 40 and 120 minutes and in thepresence.

References Cited in the file of this patent UNITED STATES PATENTSBurghart Apr. 22, 1924 Starrels Feb. 12, 1929 -12 Scott et a1 Oct. 29,1935 Woodhouse et al Dec. 15, 1942 Keim Aug. 28, 1945 Bigot Aug. 19,1952 Blinka et a1 Aug. 4, 1953 Hill Oct. 4, 1955 FOREIGN PATENTS GreatBritain Nov. 16, 1948 OTHER REFERENCES Merritt L. Kastens: Alcohol bySodium Reduction, Ind. and Eng. Chem. vol. 41, No. 3, March 1949.

15 Groggins: Unit Process in Organic Chemistry, pgs.

616-620, 4th ed., 1952 (McGraw-Hill Book Co.).

1. A PROCESS WHICH COMPRISES HEATING CRUDE ESTERS OF FATTY ACIDS HAVINGFROM 8 TO 40 CAROBON ATOMS PER MOLECULE WITH A MINERAL ACID UNDERESSENTIALLY REFLUX CONDITIONS IN THE PRESENCE OF A MONOHYDRIC ALCOHOLAND DISSOLVED IN AN INERT ORGANIC LIQUID SELECTED FROM THE GROUPCONSISTING OF HYDROCARBONS, ETHERS, AND EXCESS ALCOHOL, FOR A PERIODSUFFICIENT TO GENERATE MORE THAN THE THEORETICAL QUANTITY OF WATER BASEDUPON ESTERIFICATION OF THE FREE FATTY ACIDS AND THE MOISTURE CONTENT OFTHE STARTING MATERIALS, AND SEPARATING AT LEAST ABOUT 1.05 THEORIES OFSAID WATER FROM THE REACTION MIXTURE DURING SAID HEATING.
 3. AN IMPROVEDPROCESS FOR THE PRODUCTION OF HIGH MOLECULAR WEIGHT ALCOHOLS FROM CRUDEESTERS OF FATTY ACIDS HAVING BETWEEN 8 AND 40 CARBON ATOMS PER MOLECULE,COMPRISING HEATING SAID ESTERS WITH A MINERAL ACID UNDER ESSENTIALLYREFLUX CONDITIONS IN THE PRESENCE OF A MONOHYDRIC ALCOHOL AND DISSOLVEDIN AN INERT ORGANIC LIQUID SELECTED FROM THE GROUP CONSISTING OFHYDROCARBONS, ETHERS, AND EXCESS ALCOHOL, AND DURING THE HEATINGSEPARATING FROM THE REACTION MIXTURE THE MOISTURE IT ORGINALLY CONTAINEDAND AT LEAST ABOUT 1.05 THEORIES OF ADDITIONAL WATER BASED UPON ESTERFICATION OF THE FREE FATTY ACIDS IN THE ESTER, AND SUBJECTING THESO-TREATED ESTERS TO AH ALKALI METAL-REDUCING ALCOHOL PROCESS TO PRODUCETHE CORRESPONDING ALCOHOLS.